Wetterich eagled the 7th and had four other birdies in his 66

Brett Wetterich fired a third-round 66 to take a one-shot lead in a closely contested Deutsche Bank Championship.

Wetterich fired an eagle and four birdies as he reached 13 under, one ahead of Arron Oberholser, who also shot 66 in his third round.

Phil Mickelson is third on 11 under and will form the second last group with Tiger Woods, who is on 10 under.

Overnight co-leader Aaron Baddeley bogeyed two of his last three holes to slip back to 10 under alongside Woods.

Woods shot a 67 but three-putted the last two holes to spoil an otherwise solid day.

Mickelson had to save par six times with six-feet putts and finished with a birdie on the 18th for a 68.

US Open champion Angel Cabrera eagled the last hole for a 65 to go to nine-under with Steve Stricker among those a further shot back after a 60-foot eagle on the 18th.

"If I go out and shoot five under like I did today, it's going to be hard to beat me, unless someone really plays a good round of golf," Wetterich said.

Rich Beem and Mike Weir, who shared the lead with Baddeley after round two, both struggled.

Beem birdied two of the last three holes for a 73 to drop him six shots back at 206.